If we created a ChatGPT bot to respond to forum threads, we likely wouldn't need anyone to respond to anything. That's a pro and a con,
These tools and the template suggestions are good. As one more possibility, once you get the dimensions you can try and have someone 3d print or CNC a piece to match the measurements, and test that.
I did that when trying to design a custom lid setup for my frag tank. Goal was to do a combo of a mesh lid using standard AL hardware store frames plus 3d printed or CNC'ed pieces for the round corners. I ended up being happy with the basic AL rectangle frame so abandoned it, but making the pieces was helpful.
The 3d printed version has an issue that filament shrinks a bit when printing, but CNC'ing a piece of acrylic wouldn't have that problem. If you figure out dimensions I have a CNC and could attempt to do a test piece if you get a cheap thin piece of acrylic to me.